Of orbits and ice ages
Though it was first suggested well over a century ago, the hypothesis that changes in Earth’s orientation relative to its orbit influence the growth and decline of ice sheets was only recently tested. As described in a paper recently published in the journal Nature, Harvard Professor of Earth and Planetary Sciences Peter Huybers confirmed that slow changes in both the tilt and orientation of Earth’s spin axis combined to help determine when the major deglaciations of the past million years occurred. “These periods of deglaciation saw massive climate changes,” Huybers said. “Sea level increased by 130 meters, temperatures rose by about 5 degrees C, and atmospheric CO2 went from 180 to 280 parts per million. We ought to understand what caused these massive changes in past climate if we are to predict long-term changes in future climate with any confidence. And at least now we know with greater than 99 percent confidence...